1. Field of the Invention
The present invention relates to a vacuum apparatus, and more particularly to a vacuum apparatus which is well suited for a case where the hysteretic control of a plurality of substrates during the preparation of the substrates having a hysteresis is required.
2. Description of the Prior Art
A prior art apparatus is described in Japanese Patent Application Laid-open No. 35513/1987. It will now be explained. Substrates are introduced through an introducing chamber, and are placed on a substrate setting disc. The setting disc is rotated, and the substrate is shifted into a growth chamber (for processing), in which a crystal is grown on the substrate. Thereafter, the substrate is brought back to the setting disc and is shifted into a delivery chamber. The substrate is taken out of the apparatus through the delivery chamber.
In the molecular-beam epitaxy apparatus of the prior art, controlling the hysteretic aspects of the individual substrates is not considered at all in spite of the fact that the substrates on the substrate setting disc undergo various hysteretic aspects such as the removal of the water content of the substrate, prebaking for surface cleaning, waiting for the crystal growth, the end of the crystal growth, and the end of the surface analysis of the crystal.